Background

The publicity of the H1N1 pandemic increased the demand for flu vaccination including in the egg allergic. The MMR protocol is safe but cumbersome. A simpler but less tried protocol with vaccines having < 1.2 μg/ml egg protein has been available. [1] As current Canadian seasonal and H1N1 vaccines fulfill this criterion, we hypothesized either split or full administration is safe without skin testing.

Materials and methods

Egg allergic individuals were administered the H1N1 (n = 50) and/or the seasonal influenza (n = 31) vaccines in fall 2009. Twenty-one patients received skin prick and intradermal testing to vaccine prior to administration. Individuals with negative skin tests or those able to eat hidden egg received the full vaccine as a single shot. Those with positive skin tests or those unable to eat hidden egg were given the vaccines in a split dose (10% of total dose, followed by 90% if no reaction after 30 minutes). Patients were observed for one hour.

Results

No positive skin tests or allergic reactions were seen in the patients receiving the H1N1 vaccine (n = 50). Three patients had a positive intradermal test to the seasonal influenza vaccine but no immunization reaction. Three patients (9.7%) had transient local reactions to the seasonal influenza vaccine.

Conclusions

No significant reactions were seen in egg-allergic individuals receiving the H1N1 or seasonal influenza vaccines for a total of eighty-one vaccinations. Positive skin tests for the seasonal influenza vaccine were not predictive of subsequent allergic reaction.

Authors’ Affiliations

(1)

Department of Pediatrics, Division of Allergy, University of British Columbia, BC Children’s Hospital